1. Field of The Invention
This invention relates to photographic film developing apparatus of the type in which a film holder is moved in a circular path to a series of processing stations. The film holder is indexed from station to station and at the respective stations in lowered into and raised out of the station.
2. The Prior Art
It is known to develop photographic film in apparatus of the general type described above. See for example the following U.S. Pat. Nos.: 741,213, issued Oct. 13, 1903; 785,113, issued Mar. 21, 1905; 1,233,109, issued July 10, 1917; 2,544,644, issued Mar. 13, 1951; 2,723,610, issued Nov. 15, 1955; 2,975,695, issued Mar. 21, 1961; 3,010,377, issued Nov. 28, 1961; 3,412,667, issued Nov. 26, 1968; 3,722,384, issued Mar. 27, 1973; 4,011,573, issued Mar. 8, 1977; 4,410,257, issued Oct. 18, 1983; and 4,497,559, issued Feb. 5, 1985. These patents disclose various features of the general type of apparatus to which the present invention relates. They do not, however, disclose various distinguishing features of the invention, for example, the concept of achieving film holder agitation by reciprocation as carried out by the present invention, the structure by which the film holders are raised from and lowered into the respective stations and indexed to the next station, the novel loading station construction, the novel film holder structure, or the use of magnetic means to releasably attach the film holders to the structure which raises and lowers them and indexes them to successive stations.
These and other features of the invention provide a novel and highly efficient processing apparatus which can operate with a minimum of human intervention, and which operates reliably without the enormous complications found in the prior art use of numerous cams, pulleys, chains and the like.